JP2014014919A - Chip removing scraper and broach machine including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a chip removing scraper that has high chip removing performance, causes no damage to a cutting tool and has a long life and high versatility; and a broach machine using the chip removing scraper.SOLUTION: Slits 8 are respectively disposed outward from an edge portion of a hole 7 of each of extremely thin metal plates 2, and an outer edge 3 of the extremely thin metal plate is held and secured by rigid members 4 and 5. A chip removing scraper 1 includes the two or more extremely thin metal plates stacked one upon another so as to shift their phases. When the chip removing scraper 1 is attached to a broach machine 30 and a broach 20 is returned to an original position after machining a workpiece 32, chips adhered to a cutting edge 22a of the broach 20 are scraped while bringing the edge portion of the hole 7 into contact with a flank surface of the cutting edge 22a.

Description

  The present invention relates to a scrap for scrap removal that scrapes and removes scraps attached to a cutting edge of a cutting tool, and a broaching machine having the scraper.

  Conventionally, in order to remove the cutting waste adhering to the cutting tool by cutting, a brush made of resin (including natural, synthetic rubber, etc.), copper, steel, etc. is provided, and the cutting tool is moved relative to the cutting tool. Rotating contact or passing contact with the cutting edge. For example, in Patent Document 1, in a broaching machine that performs intermittent cutting, a circular chip brush made of nylon contacts or rotates on the outer periphery (cutting edge or groove) of the inner broach when the broach returns to the axial direction after workpiece processing. Chips are removed by contact. Moreover, in patent document 2, the cutting brush of a broach is made to contact or rotationally contact the rotating brush which rotates around an axis | shaft, and the chip is removed.

  However, resin brushes, such as nylon brushes, are highly consumed and poor in durability. In addition, when a cutting agent such as a cutting fluid is not used, or when a small amount of mist cut or dry cut is used, there is a problem that the temperature increases and the life is shortened. Further, a hard metal brush or a brush with a large brush diameter has a high chip removal rate, but may damage the tool (cutting edge). On the other hand, a soft resin brush or a brush with a small brush diameter does not damage the tool, but has a problem that the chip removal rate is low.

  On the other hand, in Patent Document 3, while moving the resin core used for casting in the axial direction, it passes through the copper brush and scraper made of many copper wires to remove carbide on the surface of the resin core. ing. However, details of the scraper are not described.

  Moreover, in patent document 4, the scraper which consists of an ultra-thin metal plate which removes the trim waste remaining in the trimmer which trim-formed the welding part is disclosed. In the trimmer, a plurality of cutting edges are formed in the axial direction, and the weld is sequentially cut by the plurality of cutting edges by moving the trimmer in the axial direction. The cutting waste adhering to the cutting edge is moved relative to the outer shape of the trimmer with a 0.01 to 2 mm thick ultrathin metal plate having a recess corresponding to the outer shape of the trimmer (moving in the direction perpendicular to the axis), Cutting chips adhering to the trimmer are removed. Since the scraper allows the outer shape of the trimmer to pass therethrough, a clearance (clearance) of 0.1 to 10 mm is provided between the outer shape of the trimmer and the outer shape of the scraper. Further, the scraper is reinforced with a reinforcing member in order to receive chip removal resistance. An external difference between the scraper and the reinforcing member is set to 1 mm or more so that chips do not bite into the auxiliary plate. On the contrary, since the scraper is an ultra-thin metal plate, the waist of the scraper becomes weak, so that the external difference between the reinforcing plate and the scraper is 1 to 30 mm.

JP 2002-103133 A JP 2011-173217 A Japanese Patent Application Laid-Open No. 08-090156 JP 2007-098445 A

  However, in a scraper like patent document 4, it must manufacture with the shape according to the axial cross section of the tool which has a cutting edge, and a process man-hour becomes excessive. In addition, there is a problem that the versatility is poor. Further, in a broach having a large number of cutting edges in the axial direction, it is completely out of the question to create a scraper having a shape corresponding to the axial cross section. Further, when Patent Document 4 is applied to Patent Document 3 to form a scraper that matches the axial cross section, the number of cutting edges is reduced, but the same problem still remains.

  In view of such problems, an object of the present invention is to provide a scraper for scrap removal that has high chip removal capability, does not damage a cutting tool, and has a long life and high versatility. Moreover, it is providing the broaching machine which has it.

  In the present invention, an ultrathin metal plate having a thickness of 0.01 to 0.2 mm, a hole opened in the ultrathin metal plate, and three or more provided outward from the edge of the hole The above-mentioned problems have been solved by providing a scraper for removing scraps having a slit and an outer edge having a width provided outside the slit.

  That is, by reducing the plate thickness, providing three or more slits outward from the edge of the hole, and securing the length and width of the deformed portion, even if a force is applied in the plate thickness direction, some spring force is applied. It is deformed while having (resistance force), and the passage of the cutting blade or the like is allowed. On the other hand, the chips are relatively moved so as to trace the surface of the cutting tool and the chips adhering to the cutting blade are removed.

  As specific specifications for carrying out such removal action, the thickness of the ultra-thin metal plate is 0.01 to 0.2 mm, preferably 0.02 to 0.08 mm, in order to obtain a spring force and flexibility. The number of slits is 3 or more, preferably 8 or more and 36 or less, more preferably 16 to 20, and the slit length is 1/4 to 2 times the maximum width of the hole, preferably about 1/2 of the maximum width of the hole. It is. The slit width is preferably about 0.2 to 2 mm from the viewpoint of workability. As a material for the metal plate, a corrosion resistant material such as SUS may be used in order to avoid the influence from the cutting fluid or the like.

  According to a second aspect of the present invention, a rigid member for sandwiching and fixing the outer edge is provided. The outer edge may be fixed to a broaching machine, which will be described later, but a thin plate of 0.2 mm or less is easily deformed by handling and storage as it is. However, deformation can be prevented by pinching and fixing the outer edge with a rigid member, and the slit portion can be made sure.

  Furthermore, in the invention described in claim 3, the slit extends from the center of the hole in a radial direction or a direction perpendicular to the side of the hole. The slit direction may be provided so as to trace the surface of the cutting tool, but the holes are often circular or polygonal, and preferably extend radially from the center. Moreover, in a polygon, you may provide in the orthogonal | vertical direction of a side other than a radial direction. It is preferable to provide a slit so that the thin plate portion is deformed in a direction in which the cutting scraps of the blade are easily scraped off.

  Furthermore, in invention of Claim 4, it was set as the scraper for cutting waste removal which piled up the said ultra-thin metal plate 2 or more. By stacking a plurality of scrapers, the strength is increased and the remaining parts are reduced.

  In the invention according to claim 5, the scraper for removing scraps in which the phases of the slits of the superposed thin metal plates are shifted is used. By shifting the phase, the spring resistance and the amount of deformation are made uniform, and the removal of chips from the slit is prevented.

  Furthermore, in the invention according to claim 6, the scrap removing scraper is used in a broaching machine, and the inside dimension of the hole is smaller than the outside dimension of the inner surface processing broach of the broaching machine. A scraper for removal was obtained. Most broaching machines are inner surface broaches, and this scrap scraper is effective. The inner surface broach is provided with a number of cutting edges in the outer periphery and the outer peripheral axis direction. By making the inner dimension (shape) of the hole smaller than the outer dimension (shape) of the inner surface processing broach of the broaching machine, the scraper hole edge sufficiently contacts along the outer shape, and the chips adhering to the cutting edge are removed. The inner dimension of the scraper hole (edge) is 3 to 5 mm smaller than the outer dimension of the inner surface broach.

  Further, in the invention according to claim 7, in the broaching machine in which the broach moves in the workpiece axial direction to process the workpiece, the scraps for scrap removal are removed when the broach is returned to the original position after the workpiece is processed. Provided is a broaching machine having a scrap removing scraper that scrapes off scraps adhering to the cutting edge while contacting an edge of the hole of the ultra-thin metal plate with a flank of the cutting edge of the broach. To do. Chips attached to the cutting edge of the broach are not scraped from the lateral direction of the cutting edge as in Patent Document 4, but are scraped from the rear, so that the chips are easily removed. In addition, the chip removal operation can be performed during the broach return process of the broaching machine processing process.

  In the present invention, the thickness of the plate is reduced, a slit is provided outward from the edge of the hole, and the length of the deformed portion is ensured so that the surface of the cutting tool can be traced when the cutting blade passes. As it moves relatively, the chips adhering to the cutting blade are removed, so that the chip removing ability is high and the cutting tool is hardly damaged. Further, it is not a needle shape such as a brush, but is a flat plate, which is strong against deformation and wear, and because it is a metal material, it is strong against heat and has a long life.

  Furthermore, in the invention described in claim 2, a hole is formed in the ultrathin metal plate, and the outer edge of the slit extending outwardly around the hole is sandwiched and fixed by a rigid member to prevent deformation, and the slit Since it is made to be flexible, it is easy to handle with a simple structure, and it is easy to manufacture and does not require a special rotating device.

  In the invention according to claim 3, since the slit is extended in a radial direction or a direction perpendicular to the side, and the slit can be provided in a direction in which cutting scraps can be easily scraped off, according to various types of cutting tools. More scraps can be scraped off. Further, since the hole shape is matched to the outer shape of the cutting tool perpendicular to the axis, the hole shape is circular or polygonal, and the hole edge is brought into contact with the cutting tool, the shape and dimensional restrictions are small and the versatility is high.

  Furthermore, in the invention described in claim 4, a plurality of scrapers can be stacked to increase the strength and to reduce the amount left behind. Further, in the invention according to claim 5, by shifting the phase of the slits, the spring resistance in the circumferential direction and the amount of deformation are made uniform, and the remaining of chips from the slit is prevented. The removal rate is improved.

  Furthermore, in the invention described in claim 6, since the inner dimension (shape) of the hole is made smaller than the outer dimension (shape) of the inner surface processing broach of the broaching machine, the scraper hole is formed along the outer shape of the inner surface processing broach. Since the edge is brought into sufficient contact and the chips adhering to the cutting blade are removed, the internal broach has a simple structure and a high chip removal rate.

  Further, in the invention described in claim 7, since the scraps on the cutting edge of the broach are scraped off from the rear in the broaching machine and the cutting chips are removed, there is little damage to the cutting edge, and damage due to the cutting edge of the scraper is also reduced. Fewer blades and scrapers have a longer life. In addition, the removal of chips is the time when the broach is returned to its original position after machining the workpiece, and no new work time is required, so there is little influence on the cycle time and no support for production.

It is a top view which shows the example of the shape of the processing hole of an internal surface broach using the scraper for cutting waste removal of this invention. BRIEF DESCRIPTION OF THE DRAWINGS (a) of the scraper for scrap removal which shows 1st embodiment of this invention is a top view, (b) is the sectional view on the AA line of (a). (A) of the scraper for scrap removal which shows 2nd embodiment of this invention is a top view, (b) is the BB line | wire partial expanded sectional view of (a). It is a top view of the scraper for cutting waste removal which shows 3rd embodiment of this invention. It is a top view of the scraper for cutting waste removal which shows the 4th embodiment of this invention. It is a top view of the ultra-thin metal plate of the scraper for cutting waste removal which shows the 5th embodiment of this invention. It is a top view of the ultra-thin metal plate of the scraper for cutting waste removal which shows the 6th embodiment of this invention. It is a top view of the ultra-thin metal plate of the scraper for cutting waste removal which shows the 7th embodiment of this invention. It is a top view of the ultra-thin metal plate of the scraper for cutting waste removal which shows the 8th embodiment of this invention. It is a processing process figure which shows the example which attached the scraper for cutting waste removal of the present invention to a broaching machine, (a) is the original position of a broach, (b) is before work processing, (c) is the end of work processing, (d) is an explanatory view showing a state where the workpiece is exchanged, (e) is when the broach is returned and when cutting waste is removed, and (f) is a state where the broach is returned to the original position and the workpiece is placed.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an example of the shape of a processed hole when the scraper for scrap removal according to the present invention is applied to an inner surface broach. As shown in FIG. 1, the shape of the processing hole of the inner surface broach varies. For example, what is shown in FIG. 1A is an example of a hole into which a shaft such as a round shape, a D shape, an oval shape, or a deformed oval shape is fitted in order from the left. Broaches that process such holes are called round broaches.

  Moreover, what is shown in FIG.1 (b) is an example of a gear hole or a spline hole. Broaches that machine such holes are called special spline broaches. FIG. 1C shows examples of holes such as a quadrangle, a hexagon, an octagon, and a deformed quadrangle in order from the left. Broaches that process such holes are called square broaches. FIG. 1 (d) shows an example of a serration hole. Broaches that process such holes are called chevron serration broaches. Moreover, what is shown in FIG.1 (e) is an example of the composite hole of a square hole and a spline or a serration hole. Broaches that machine such holes are called square spline broaches. Further, as shown in FIG. 1 (f), an inner surface broach is used for processing holes having various shapes.

  As shown by a dotted line and a reference numeral 20 in FIG. 2, the inner surface broach 20 is simply described. The front broaching portion 37 for pulling out the broach and the front guide portion 39 for positioning along a pilot hole previously opened in the workpiece. Subsequently, a large number of cutting edges 22a are provided in the circumferential direction and the axial direction. The cutting edge is formed in a circumferential shape and an axial shape so as to be gradually finished in the shape of the machining hole shown in FIG. 1, and a part or all of the circumferential width and height of the cutting edge is gradually increased in the axial direction. Yes. Such an inner surface broach is well known and will not be described in detail.

  The scraper for removing scraps of the present invention is a scraper suitable for removing chips adhering to the cutting edge of the inner surface broach. The shape of the scraper is manufactured in accordance with the outer shape of the inner surface broach for finishing the hole as shown in FIG. Some examples will be described below.

  A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 2, the scraper 1 for scrap removal according to the first embodiment includes an ultrathin metal plate 2, two annular rings 4 and 5 that sandwich an outer peripheral edge 3 of the ultrathin metal plate, A bolt (fixing member) 6 is provided for clamping and fixing the ultrathin metal plate to the ring. A hole 7 is formed in the center of the ultrathin metal plate 2, and slits 8 are provided equally in a radial direction from the center of the hole. The outer periphery of the ultrathin metal plate 2 has a circular shape concentric with the hole, and the ultrathin metal plate 2 has a donut disk shape. The hole diameter D is dimensioned so as to extend from the outer shape 21 (d) of the tool 20 indicated by the dotted line inserted through the hole to which chips to be removed are attached.

  The ultrathin metal plate 2 is a thin plate having a thickness t of SUS304 of 0.05 mm. The number of slits 8 is 18, the width s is 0.5 mm, and the length L is substantially the same as the hole diameter D. The inner circumferences 4 a and 5 a of the rings 4 and 5 are the same as the positions of the end portions 8 a of the slits 8.

  Next, a second embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 3, a scraper 1A for scrap removal according to the second embodiment has two ultrathin metal plates 2 and 2 of the scraper for scrap removal according to the first embodiment, and is further shifted in phase. Is.

  The same components as those described above are denoted by the same reference numerals and description thereof is omitted. Although the ultrathin metal plates 2 are directly stacked, a thin ring may be sandwiched between the ultrathin metal plates 2 and 2, and may be sandwiched between the rings 4 and 5. The number of ultrathin metal plates may be three or more. As a result, the strength is increased, and the remaining amount is reduced, the spring resistance in the circumferential direction and the amount of deformation are made uniform, and the remaining of chips from the slit is prevented.

  The third embodiment of the present invention will be described with reference to the drawings. The same components as those described above are denoted by the same reference numerals and description thereof is omitted. The scraper 1B for removing scraps according to the third embodiment is applied to a tool whose outer shape is not a cylindrical shape and a cutting edge is provided in part. For example, a broach as shown in FIGS. 2 to 7 of JP-A-2005-1089.

  As shown in FIG. 4, a cutting tool 20A indicated by a dotted line is an inner diameter grooving broach, and has a substantially diamond-shaped cross-section blade portion 22 having a semicircular grooving cutting edge 22a protruding on a part of the outer periphery. The blade holding part 23 is provided for holding the blade part and holding the broach 20A along the work inner diameter during processing. Others are the same as described above.

  The fourth embodiment of the present invention will be described with reference to the drawings. Components similar to those in the third embodiment are denoted by the same reference numerals and description thereof is omitted. The scraper 1C for cutting waste removal according to the fourth embodiment is configured such that the slits are more accurately arranged with respect to the third embodiment. As shown in FIG. 5, in addition to the hole 7 in the center of the ultrathin metal plate 2, a notch hole 7A is formed around the center 22c of the cutting edge, and a slit 8A having a small inter-slit width is provided. Other portions are provided with the same slits 8 as described above. The edge of the cutout hole 7A is dimensioned to extend from the cutting edge 22a to the center of the cutting edge. In other portions, the dimensions are appropriately set so as to be in contact with or not in contact with the blade holder 23 depending on the state of the chips.

  The fifth embodiment of the present invention will be described with reference to the drawings. Components similar to those described above are denoted by the same reference numerals, and description thereof is omitted. In addition, it demonstrates taking the case of the ultra-thin metal plate which comprises the scraper for cutting waste removal. As shown in FIG. 6, the ultrathin metal plate 2B of the scraper for scrap removal according to the fifth embodiment is an example applied to a square broach for processing a hexagonal hole. The slits 8 are provided radially with respect to the central hexagonal hole 7B. The slits 8 extend radially from the apex and sides of the hexagonal hole 7B. The slits are formed at right angles to the sides at the same time. The outer edge 3 is sandwiched between the rigid members 4 and 5 by the bolt 6 described above. The outer edge 3 is provided with four holes 2d through which the bolt screw portion passes.

  Furthermore, a sixth embodiment of the present invention will be described with reference to the drawings. Components similar to those described above are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 7, the ultrathin metal plate 2C of the scraper for scrap removal according to the sixth embodiment is an example applied to a square broach for processing a shaft hole and a key groove for parallel key holes. Also in this case, slits 8 are provided radially with respect to the hole 7C. The slits extend radially from the bottom and sides of the hole. The slits are formed at right angles to the sides at the same time. The position of the slit 8 is set so as to efficiently remove the cutting waste in accordance with the hole shape.

  The seventh embodiment of the present invention will be described with reference to the drawings. Components similar to those described above are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 8, the ultrathin metal plate 2D of the scraper for scrap removal according to the seventh embodiment is an example for a square broach for processing a square hole. The slits 8 are provided radially with respect to the square hole 7D.

  Furthermore, an eighth embodiment of the present invention will be described with reference to the drawings. Components similar to those described above are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 9, the ultrathin metal plate 2E of the scraper for scrap removal according to the eighth embodiment is an example in which the slit according to the seventh embodiment is changed. The slit 8 is formed in a direction perpendicular to the side of the rectangular hole 7D. In this case, it comes into contact with the entire cutting edge of the broach.

  As described above, the scraper removing scraper of the present invention can be in various forms. Radial slits are provided in a perforated ultra-thin metal plate to ensure the length of the deformed part, and even if it receives a force in the thickness direction, it has some spring force and allows the cutting blade to pass through. . At the same time, it is possible to remove chips adhering to the cutting edge by relatively moving so as to trace the surface of the cutting tool. Further, since it is plate-like, it is firmer than a brush, has high strength, has little wear, and has a long life. In addition, chips and the like are rarely entangled like a brush, and it is easy to remove the chips and the like attached to the scraper side. Further, if the material of the ultra-thin metal plate is made of a resin such as rubber, it is inferior in terms of strength, wear, heat resistance and the like.

  An embodiment in which such a scrap removing scraper is used in a broaching machine will be described. As shown in FIG. 10 (f), the inner surface broaching machine 30 is provided with a work table 33 for placing a work 32 having a pre-processed hole 32 a to be processed on a base 31. The work table 33 can be reciprocated in the left-right direction as seen in the figure between a machining position 34 for broaching the work 32 and a set position 35 for attaching and removing the work. The scraper 1 for removing scraps is provided on the right side of the work placement position 33a on the work table. The scraper 1 for cutting waste removal is set to the processing position 34 at a position where the work table 33 is moved so that the work 32 is set to the work set position.

  As shown in FIG. 10, the broach 20 for machining the workpiece 32 is vertical so that a large number of cutting edges 22 a face downward, moves in the vertical direction, and passes through the workpiece pre-working holes 32 a, thereby 32 is broached. The rear grip 36 at the top of the broach 20 is gripped by a lifting clamp (not shown), and the broach is suspended or pulled upward. Further, the front gripping portion 37 at the lower part of the broach is pulled down and broached by the front clamp 38.

  As shown in FIGS. 2 to 9, the broach 20 is an internal gear machining broach provided with a large number of gear-shaped cutting edges 22 a on the outside, and forms a gear-shaped outer shape 21. Further, the edge of the hole 7 of the scraper 1 for scrap removal extends inward from the outermost diameter d of the outer shape 21 of the broach 20.

  The operation of the internal broaching machine 30 will be described with reference to FIG. In FIG. 10A, the work table 33 on which the work 32 is placed is set at the processing position 34. At this time, the broach 20 is lifted to the original position above the workpiece by a lifting clamp so as not to interfere with the workpiece. Next, as shown in (b), the broach 20 is lowered 41, the front gripping portion is passed through the workpiece pre-working hole 32a, the front clamp 38 is gripped, and the lifting clamp is released. Further, as shown in (c), the front clamp 38 is lowered, the broach 20 is pulled out, and the broaching of the pre-processed hole 32a is completed.

  Next, as shown in FIG. 10 (d), the work table 33 is moved to the left 42 as viewed in the figure so that the cutting scrap removing scraper 1 is at the machining position 34. Subsequently, as shown in FIG. 10E, the front clamp 38 is raised 43, the rear grip portion 36 is gripped by a lifting clamp (not shown), the front clamp 38 is released, and the broach 20 is pulled up by the lifting clamp. When the broach 20 is lifted 43, scraping off cutting chips adhering to the cutting edge while bringing the edge of the hole 7 of the ultrathin metal plate into contact with the flank of the cutting edge 22a. Then, as shown in FIG. 10 (f), the broach 20 is returned to the original position, the work table 33 is moved in the right direction 44, and the process returns to FIG. 10 (a). 10 (d) to 10 (f), the work 32 is removed and a new work is placed.

  Thereby, the chips adhering to the cutting edge 22a of the broach 20 are scraped by the scraper not from the side of the cutting edge or from the front but from the rear. Further, the chip removal operation can be performed during the broach return process FIG. 10E of the broaching machine processing process. In this way, by reducing the plate thickness, providing radial slits, and ensuring the length of the deformed part, even if force is applied in the plate thickness direction, it will resist to some extent and allow the passage of cutting blades, etc. And moving relative to trace the surface of the cutting tool to remove chips adhering to the cutting edge. Needless to say, a plurality of similar or other scrapers may be arranged, or a brush or other removing device may be used in combination.

1, 1A, 1B, 1C Scraper for scrap removal.
2, 2A, 2B, 2C, 2D, 2E Ultra-thin metal plate 3 Outer edge 4, 5 Rigid member, ring 7, 7A, 7B, 7C, 7D Hole 8, 8A Slit 20 Broach 21 Broach outline 22a Cutting blade 30 Brooch Panel 32 Work d Broach outer diameter D Maximum hole width, diameter L Slit length t Thickness

Claims (7)

  An ultrathin metal plate having a thickness of 0.01 to 0.2 mm, a hole formed in the ultrathin metal plate, three or more slits provided outward from an edge of the hole, A scraper for removing cutting waste, comprising: an outer edge having a width provided outside the slit.   The scraper for scrap removal according to claim 1, further comprising a rigid member that sandwiches and fixes the outer edge.   3. The scraper for scrap removal according to claim 1, wherein the slit extends in a radial direction or a direction perpendicular to the side of the hole from the center of the hole.   The scraper for scrap removal according to claim 1, wherein two or more of the ultrathin metal plates are stacked.   The scraper for scrap removal according to claim 4, wherein the phases of the slits of the superposed thin metal plates are shifted from each other.   The scraping scrap removing scraper is used for a broaching machine, and the inner dimension of the hole is smaller than the outer dimension of an inner surface processing broach of the broaching machine. The scraper for removing scraps as described.   In an inner surface processing broaching machine in which a broach moves in the workpiece axial direction to process the inner surface of the workpiece, the scraping scraper for scrap removal is a flank of the cutting edge of the broach when the broach is returned to the original position after the workpiece is processed. 7. A broach having a scraper for scrap removal according to claim 6, wherein scrapes attached to the cutting edge are scraped off while contacting an edge of a hole of the ultrathin metal plate. Board.

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